A semiconductor chip implemented such as on a board of an electronic appliance is produced by dicing a semiconductor wafer partitioned by streets (dicing line), along the streets. As a method of dicing a semiconductor wafer, a mechanical method using a dicing saw is known. Besides, in recent years, plasma dicing, which is a method of cutting off by plasma etching, has been devised (patent literature 1).
In such a method of manufacturing semiconductor chips using plasma dicing, a sheet-like supporting member (protective sheet) is first stuck onto the circuit-forming surface of a semiconductor wafer so as to cover the entire circuit-forming surface, and then a mask layer (mask member) with etching resistance is formed on the surface (back surface) opposite to the circuit-forming surface. Next, laser light is irradiated on the mask layer along streets to form a mask pattern; a semiconductor wafer with the mask pattern formed on its mask layer is carried into the vacuum chamber of a plasma dicing apparatus; and then the semiconductor wafer is mounted on the stage (mounting stage) inside the vacuum chamber so that the mask layer faces upward. Then, plasma is generated in the vacuum chamber to perform plasma etching on the semiconductor wafer with the mask layer on which the mask pattern is formed as a mask; and the semiconductor wafer is diced into individual semiconductor chips.
However, a semiconductor wafer is extremely vulnerable such as to shock before being diced into individual semiconductor chips by plasma dicing, which requires careful handling when carrying the semiconductor wafer into and out of the vacuum chamber, which causes poor workability.    [Patent literature 1] Japanese Patent Unexamined Publication No. 2005-191039